Apparatus for automatically positioning the thread field of a fabric to be fringed



Dec. 22,l 19701 G B. POZZOLO 3,548,470

APPARATUS FOR AUTOMATICALLY POSITIONING THE THREAD l-lPLD 0F A FABRIC TO BE FRINGED Filed Nov. 14,-' 1967 2 Shvetshuet 1 De.22,197o `G B, POZZQLQ 3,548,470

APPARATUS FOR AUTOMATICALLY POSITIONING THE THREAD FIELD OF A FABRIC TO BE FRINGED Filed Nov.`l4, 1967 2 Sheets-Sheet 2 U. C. SouRce FIGA- FEED 5oz/Rcs ExHAusr FRINGING MECHN'W THREAD Flew /To BE Fmwaen a: f f ELECrRlc O v PosmoN/NG AFEELER FRmamG Mecunmsn f fuamc DRIVE ELEcrR/c Cvuuaslz y A T TORNEYS United States Patent O 3,548,470 APPARATUS FOR AUTOMATICALLY POSITION- ING THE THREAD FIELD F A FABRIC TO BE FRINGED Giovanni Battista Pozzolo, Lovere, Italy, assigner to S.M.I.T. Societar Macchine per llndustria Tessile Societa per Azioni Filed Nov. 14, 1967, Ser. No. 683,399 Claims priority, application Italy, Nov. 15, 1966, 29,922/ 66, Patent 782,953 Int. Cl. D06c 29/00 U.S. Cl. 28-18 6 Claims ABSTRACT Olii THE DISCLOSURE Apparatus for automatically stopping the fabric carried by a fringing machine so that the warp thread field to be fringed is centered under tension on the center line of the fringing mechanism. The movement of the fabric is directly monitored by a freely rotating cylinder which transfers the movement through alternately embodied mechanisms to a cam plate. First and second electric measuring feelers in contact with the fabric actuate the mechanisms which, in turn, cause the cam plate to pivot and actuate a switch which stops the fabric with the thread field centered. The pivoting cam may also actuate a switch which reduces the speed of the fabric just prior to its being stopped.

BACKGROUND AND OBJECTS OF THE INVENTION The present invention relates generally to automatic fringing machines, and relates more particularly to apparatus in such machines positioning the thread field of the fabric being fringed under tension on the center line of the fringing machine.

In order for the fringing operation to be fully successful, it is important that the fabric and the warp threads in the thread field to be fringed be maintained under a strong tension, which prevents the disarrangement of the thread field and also serves to permit rearrangement of a thread field made disorderly by preceding treatments to the fabric. Thus, a good subdivision of the warp threads into bundles, effected by the dividing and collecting combs, requires that the thread lfield be properly tensioned, the latter being effected by a pair of opposed rows of resilient pin members which are inserted into the thread field and moved in opposite directions, more fully described herein below.

It is desirable that the manual operations, especially those requiring a particular care of the operator, be replaced by automatic operations for the benefit of increased productivity by the machine and for the quality of the product.

As heretofore practiced, the fabric is transported through the fringing machine under a weak tension, being transported by a driving cylinder which imparts a modcrate speed to the fabric. As the thread field to be fringed arrives at the location of the first row of resilient pins, the operator lowers the guard for the pins, permitting the pins to enter the thread field across the entire width thereof, thereby fixing every wrong position of the individual threads. Finally, upon the first row of pins contacting the border of the thread field, they stop the movement of the fabric, whereupon it begins to slide on the dragging cylinder. At this point the operator lowers the guard of the second row of resilient pins, permitting these pins to also enter the thread field, and then switches off the electric current to the dragging motor, leaving the fabric loosely suspended but stationary between the Uwo rows of resilient ICC pins. The two rows of resilient pins are then operated to first center the thread field on the center line of the machine and to then be moved in opposite directions so as to stretch the thread field.

Accordingly, as heretofore practiced, the attention which is required by the operator, who, among other things, has to insert at the right time the resilient pins into a thread field in motion, is considerable and the number of quick manipulations is high, the manipulations being necessary only for the stretching operation (three direct manipulations of compressed air valves and a push-button electric manipulation being required). Moreover, it is not possible to let the fabric run under tension without risking damage to both the fabric and the resilient pin members.

=It is therefore the object of the present invention to eliminate the aforesaid drawbacks of the prior art and to provide a new and improved apparatus whereby the fabric may be run under a strong tension and may be stopped automatically with the warp thread eld to be fringed located exactly centered on the center line of the fringing machine, regardless of the length of the thread field or the distance between individual thread fields. As a consequence thereof, the two opposed parallel rows of resilient pin members may be inserted into the thread field at the same time and the field place-d under a high tension without again moving the fabric.

Objects and advantages of the invention are set forth in part herein and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

-lt will be understood that the foregoing general description and the following detailed description as well are exemplary an'd explanatory of the invention but are not restrictive thereof.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate preferred embodiments of the invention, and together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a view in elevation, partly sectional and partly diagrammatic, of apparatus embodying the present invention for automatically centering the thread fields of a fabric to be fringed on the center line of the fringing machine;

FIG. 2 is a view taken along line 2-2 in FIG. 1;

FIG. 3 is a schematic View illustrating the operation of an oleodynamic motor for driving the fabric through the fringing machine;

FIG. 4 is a schematic View illustrating the operation of a D.C. motor for driving the fabric through the fringing machine, illustrated as an alternate embodiment to FIG. 3; and

FIG. 5 is a fragmentary schematic view of a fringng machine illustrating the location of the electric measuring and positioning feelers of the invention.

DESCRIPTION OF T-HE PREFERRED EMBODIMENTS lReferring now more particularly to FIG. l of the accompanying drawings, there is schematically illustrated a pinion gear l, which is rotated, through a suitable universal joint 2', by freely rotating cylinder 3, the latter advantageously being coated with a greater gasket (not shown) and mounted in contact with the fabric carried by the machine so as to be, in turn, rotated by the fabric. By obtaining a motion directly responsive to the movement of the fabric, the parameters of time and speed are eliminated, and an easy and reliable positioning means may be realized, whatever the speed of the fabric, the length of the thread field, or the distance between individual thread fields.

Pinion gear 1 transmits the rotary motion of cylinder 3 to shaft 5 through pinion gear 6, which is secured to shaft 5 for rotation therewith.

On the shaft 7, which is suitably supported by the two opposed bearing plates 24 and 25, are keyed the counterdisks 26 and 27 of two electric toothed clutches 8 and 9 and the cam plate 16, the latter of which is best seen in FIG. 4.

The main disks 28 and 29 of the clutches 8 and 9 are secured to pinion gears 6 and 10, respectively, which in turn are keyed to the shafts `5 and 30, respectively.

The shafts 5 and 30 are coaxial with shaft 7 and are supported for rotation thereabout through pairs of roller bearings 31.

Pinion gears 11 and 12, keyed on shaft 13 for rotation therewith, and pinion gear 14, mounted on idler shaft 15, in meshing engagement between gears 6 and 1f), constitute a train gear drive for transmitting and for reversing rotary motion between gears 6 and 10. Advantageously, the gear ratio for the gear couple 6, 11 is 2:1 and for the gear couple 12, 10 is 1:1.

It will be apparent from the foregoing that if pinion gear 1 turns clockwise, pinion gear 6 and, accordingly, the main disk 28 of the clutch 8 will turn idle onthe shaft in a counterclockwise direction. The pinion gears Y 11 and 12 will also turn clockwise and thus pinion gear 14 turns counterclockwise whereby pinion gear 1f) as well as the main disk 29 of the clutch 9 will tum clockwise, idle on shaft 7. Hence, if pinion gears 11, 12' and 10 have a number of teeth which is half that of pinion gear 6, it

follows that pinion gear 10 will turn not only in a direction opposite to the direction of rotation of pinion gear 6 but also at twice the speed.

Accordingly, by connecting the shaft 7 with pinion gear 6 through the clutch i8, cam plate 16 will turn counterclockwise, whereas, by connecting the shaft 7 with pinion gear 10 through the clutch 9, cam plate 16 will turn in an opposite direction (clockwise) and at a double speed.

In accordance with the invention, clutch 8 is excited by a first electric measuring feeler, arranged on the path of the fabric at a distance from the center line of the fringing machine at least equal to the maximum width of the thread fields to be fringed (see FIG. 5).

Thus, when the front edge of a thread field to be fringed is sensed by the first measuring feeler, it transmits an electric signal exciting the electric tooth clutch 8, the moving element 32 of the clutch 8, sliding with its square teeth 33 in corresponding cavities at the periphery of the main disk 28, with which it is at all times connected, is thereby shifted until its teeth 34 engage the corresponding teeth 35 of the counterdisk 26. In this way, the shaft 7 and cam plate 16. are made integral with the pinion gear 6 and turn counterclockwise for the whole time of excitation of the clutch 8, i.e., until the whole length of the thread field has passed over the measuring feeler. The cam plate 16 therefore turns counterclockwise through an arc proportional to the length of the thread field and then stops.

A second electric positioning feeler (FIG. 5) is arranged in correspondence with the center line of the fringing machine and, upon the border of the aforementioned thread field reaching the center line it is sensed by the positioning feeler, which transmits an electric signal which actuates clutch 9. Clutch 9, in the same manner as described in connection with clutch 8, makes the shaft 7 and, accordingly, the cam plate 16 integral with the pinion gear 10. The cam plate 16 therefore again starts to turn, but in a direction opposite (clockwise) to the preceding one and at twice the speed. Hence, cam plate 16 runs again along the aforementioned are and reaches Cil its initial position in half the time, at which time one-half the length of the thread field ofthe fabric will have passed over the positioning feeler.

Upon reaching its initial position, cam plate 16 closes the electrical contacts 36 of the microswitch 17 (see lFlG. 2), the latter operating to stop the fabric drive motor more fully descrilbed hereinafter. Since the positioning feeler is located on the middle line of the fringing machine, it follows that at the stopping of the motion of the fabric, the thread field will be centered on the middle line of the fringing machine.

It will thus be seen that the thread field to be fringed is blocked under tension exactly centered as to the center line of the fringing machine, thus allowing an easy and correct penetration and subdivision of the field by the resilient pin members.

The feeding speed of the fabric may be as high as desired, as it need not be limited in order to allow the operator to perform the aforementioned manipulations on the fabric in motion and because there is no longer any danger of damaging either the fabric or the resilient pins.

In order to reach a quite exact positioning of the thread fields, independent of the degree of the passive resistances and of the inertia of the masses in movement, the apparatus according to the invention also includes a system for providing a slow advance of the fabric during the last portion of its travel just prior to reaching a thread field.

To this end, referring now more particularly to FIG. 3, the fabric is preferably driven by a suitable oleodynamic motor, indicated schematically at 44, the latter being controlled by slide valve 45, which is actuated by microswitch 17. Thus, in the position shown in solid lines, the motor is on, -but upon valve 45 being shifted to the position shown in dotted lines, the feeding of the motor is cutoff and it therefore stops.

`On the oil drain of motor 44, there is provided a second slide valve 46. When slide valve 46 is in the position indicated in solid lines in FIG. 3, the exhaust-oil 6 of the motor 44 fiows down through the duct 47; when, on the contrary, the slide valve 46 is shifted to the position indicated in dotted lines, the exhaust-oil flows down through the throat member 48 which considerably reduces the oil-iiow of motor 44 and, hence, causes the motor to slow down.

A second microswitch 18 (see FIG. 2) activated only during the return travel of the cam 16, and similar to switch 17 controls this slide valve 46 and, being arranged in an advanced position to microswitch 17 with respect to the return travel of the cam, will slow down the advancing of the fabric only in the last increments of distance of its travel.

Alternatively, as shown schematically in FIG. 4, a D.C. motor 49 may be used for driving the fabric. In this case motor 49 may be suitably fed from a DC. source through the two switches 50 and 51. Switch 50 serves to open the feeding circuit of the motor 49 and is controlled by the microswitch 17. The microswitch 18, on the contrary, moves the switch 51 from the position (o) to the position (p) inserting in this way a resistance (fR) in series with the motor feeding circuit, to thereby reduce the speed of the motor.

It will be understood that the invention in its broader aspects is not limited to the specific embodiments herein shown and described but departures may be made therefrom without departing from the principles of the invention and without sacrificing its chief advantages.

What I claim is:

1. In a fringing machine carrying a fabric having formed therein at least one :field of threads to 'be formed into fringes, and in which the fabric is moved through the machine by motor-driven conveyor rollers and the fringing mechanism is located on the center line of the machine, the improvement therein which comprises:

first means for automatically stopping said thread eld on the center line of the fringing machine under tension; and second means for reducing the speed of the fabric immediately prior to the fabric being stopped by said iirst means. 2. A fringing machine as claimed in claim 1, wherein said tirst means includes:

freely rotating cylinder means driven by the movement of said fabric; rotary motion transfer means transferring rotary motion of said cylinder means to rotationably mounted cam means,

said means adapted to rotate said cam means in a first direction corresponding to the direction of movement of said cylinder means and to thereafter return said cam means to its normal rest position at double the speed of the initial rotation; first and second electric feeler means mounted in spaced relation to one another and in contact with the moving fabric,

said -frst feeler means positioned forwardly of the center line of the machine a distance at least equal to the width of said thread field and actuating said rotary motion transfer means, so as to rotate said cam means in said first direction upon said first feeler means contacting the forward edge of said thread eld, and said second feeler means positioned on the center line of said machine and actuating said rotary motion transfer means so as to return said cam means to its rest position upon said second feeler means contacting the forward edge of said thread field; and iirst electric switch means controlling the fabric motor drive actuated upon the return of said cam means to said rest position,

said switch means stopping the fabric motor upon being actuated, thereby stopping the movement of the fabric carried lby the machine with the thread field centered on the center line of the machine.

3. A fringing machine as claimed in claim 2, wherein said rotary motion transfer means includes:

lirst and second pinion gears mounted for alternate rotation with said cam means, first and second clutch means for alternately rotating said first and second gears, respectively, with said cam means,

said rst and second clutch means being actuated yby said first and second electric feeler means, respectively, and gear train means for rotating said second pinion gear in a direction opposite to that of said iirst pinion gear and at double the speed. 4. A fringing machine as claimed in claim 1 wherein said second means includes:

means for reducing the speed Iof the motor driving the fabric conveyor rollers, and second electric switch means actuating the motor speed reduction means,

said second electric switch being arranged for actuation by said cam means immediately prior to said cam means returning to its rest position. 5. A fringing machine 4as claimed in claim 4, wherein the motor driving the fabric conveyor rollers is an oleodynamic motor and said motor' speed reduction means comprises a throat shuttle valve, whereby actuation of said valve by said second electric switch means reduces the liquid ow to said motor, thereby reducing the speed of the motor. r

6. A fringing machine as claimed in claim 4, wherein the motor driving the fabric conveyor rollers is a D.C. motor and said motor speed reduction means comprises resistance means, whereby actuation of said Second electric switch means inserts said resistance means in series with the motor feed circuit, thereby reducing the speed the motor.

References Cited UNITED STATES lTPATENTS Louis K. IRnviRoD'r, Primary Examiner 

